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Bureau of Mines Information Circular/1986 



Columbium Availability— Market 
Economy Countries 

A Minerals Availability Appraisal 

By Federick W. Miller, R. J. Fantel, and D. A. Buckingham 




UNITED STATES DEPARTMENT OF THE INTERIOR 



Information Circular 9085 



Columbium Availability— Market 
Economy Countries 

A Minerals Availability Appraisal 

By Federick W. Miller, R. J. Fantel, and D. A. Buckingham 




UNITED STATES DEPARTMENT OF THE INTERIOR 
Donald Paul Hodel, Secretary 

BUREAU OF MINES 
Robert C. Horton, Director 



As the Nation's principal conservation agency, the Department of the Interior 
has responsibility for most of our nationally owned public lands and natural 
resources. This includes fostering the wisest use of our land and water 
resources, protecting our fish and wildlife, preserving the environment and 
cultural values of our national parks and historical places, and providing for the 
enjoyment of life through outdoor recreation. The Department assesses our 
energy and mineral resources and works to assure that their development is in 
the best interests of all our people. The Department also has a major responsibili- 
ty for American Indian reservation communities and for people who live in island 
territories under U.S. administration. 





V 



Library of Congress Cataloging-in-Publication Data 



Miller, Frederick W. 

Columbium availability -market economy countries. 

(Bureau of Mines information circular;9085 )• 

Bibliography: p. 

Supt. of Docs, no.: I 28.27: 

1. Niobium industry. 2. Market surveys. I. Fantel, R. J. (Richard J.) II. Buckingham, D.A. 
(David A.) III. Title. IV. Series: Information circular (United States. Bureau of Mines);|9085 

TN295.U4 [HD9539.N542] 622 s [338.27499] 86-600050 



Ill 



PREFACE 



The Bureau of Mines is assessing the worldwide availability of selected minerals 
of economic significance, most of which are also critical minerals. The Bureau iden- 
tifies, collects, compiles, and evaluates information on producing, developing, and ex- 
plored deposits, and on mineral processing plants worldwide. Objectives are to classify 
both domestic and foreign resources, to identify by cost evaluation those demonstrated 
resources that are reserves, and to prepare analyses of mineral availability. 

This report is one of a continuing Series of reports that analyze the availability of 
minerals from domestic and foreign sources. Questions about, or comments on, these 
reports should be addressed to Chief, Division of Minerals Availability, Bureau of Mines, 
2401 E St., NW., Washington, DC 20241. 



CONTENTS 

Page Page 

Preface 'in Beneficiation methods 9 

Abstract 1 Smelting methods 10 

Introduction 2 Columbium deposit costs and evaluation 10 

Acknowledgments 2 Costing methodology 10 

Columbium industry 3 Operating costs 10 

Evaluation methodology 5 Capital costs 12 

Methodology 5 Columbium availability 12 

Deposit selection criteria 5 Economic evaluation methodology 12 

Resources 7 Total availability 13 

Geology 8 Annual availability 16 

Mining and processing of columbium 8 Conclusion 19 

Mining methods 8 References 20 



ILLUSTRATIONS 

1. Location of MEC pyrochlore deposits 3 

2. Estimated MEC mine production, 1983 4 

3. Estimated MEC ferrocolumbium production, 1983 5 

4. Flow chart of evaluation procedure 6 

5. Mineral resource classification categories 6 

6. Demonstrated columbium resources 7 

7. Typical process flowsheet for pyrochlore mill 9 

8. Operating cost comparison for columbium mines and deposits 11 

9. Estimated capital cost required to develop nonproducing deposits 12 

10. Recoverable columbium from evaluated mines and deposits 14 

11. Total cost and total recoverable columbium from MEC mines and deposits 15 

12. Total cost and total recoverable columbium from Americas as compared with data for all selected deposits 15 

13. Total cost and total recoverable columbium from nonproducers at 0- and 15-pct DCFROR 16 

14. Potential annual production from producing mines 17 

15. Potential annual production from selected nonproducers at selected ranges of total production costs 17 

16. Potential annual production from nonproducers for selected years 18 

17. Potential annual production from selected mines and deposits excluding Brazil 18 



TABLES 

1. Columbium deposit ownership and status data 2 

2. Summary of columbium resources in market economy countries 7 

3. Breakdown of operating cost expressed as a percentage of total costs H 

4. Mine, mill, and smelter operating cost by principal component 12 

5. Breakdown of capital costs required to develop nonproducing columbium deposits in North America and Africa ... 12 

6. Total recoverable tonnages of columbium and ferrocolumbium 14 



UNIT OF MEASURE ABBREVIATIONS USED IN THIS REPORT 



°c 


degree Celsius 


mt/h 


metric ton per hour 


g 


gram 


mt/yr 


metric ton per year 


g/mt 


gram per metric ton 


mm 


millimeter 


h 


hour 


Mmt 


million metric tons 


kg 


kilogram 


/*m 


micrometer 


m 


meter 


pet 


percent 


min 


minute 


lb 


pound 


mt 


metric ton 


yr 


year 



COLUMBIUM AVAILABILITY— MARKET ECONOMY COUNTRIES 
A Minerals Availability Appraisal 

By Frederick W. Miller, 1 R. J. Fantel, 1 and D. A. Buckingham 2 

ABSTRACT 



The Bureau of Mines has investigated the availability of columbium from 19 deposits (3 
producers and 16 nonproducers) in 7 market economy countries (MEC's). Brazil has the 
largest recoverable columbium resource, posessing approximately 2.39 million metric 
tons (Mmt), or 69 pet of the MEC total (3.47 Mmt). The Western Hemisphere countries of 
Brazil, Canada and the United States contain 3.14 Mmt of recoverable columbium or 90 
pet of the MEC total. Columbium recovered as a byproduct of tin mining is not included 
as part of MEC resources in this study. 

Currently producing mines are Araxa and Catalao in Brazil, and Niobec in Canada. 
These three mines have 2.42 Mmt of recoverable resources or approximately 69 pet of 
the MEC total. It is estimated that these mines, operating at full capacity, could satisfy 
cumulative MEC demand (based on an annual growth rate of 5.1 pet) for the next 20 yr. 

The United States is totally dependent upon foreign sources for its columbium supply. 
The majority of U.S. columbium is imported from Brazil in the form of steelmaking- 
grade ferrocolumbium. Canada has been the sole source of pyrochlore concentrates since 
Brazil discontinued exports in 1981. The United States also imports small (but impor- 
tant) quantities of columbium as columbite concentrates from Nigeria and Brazil, as col- 
umbite contained in tin slags from Thailand and Malaysia, and as synthetic concentrates 
from the Federal Republic of Germany. 

'Physical scientist. 
2 Geologist. 
Minerals Availability Field Office, Bureau of Mines, Denver, CO. 



INTRODUCTION 



The primary use of columbium (niobium) is as an alloy- 
ing element in steels and superalloys. It has been estimated 
that 85 to 90 pet of columbium production in market 
economy countries 3 (MEC's) is presently consumed by the 
steelmaking industry in the form of ferrocolumbium (1).* 

Columbium occurs primarily in two mineral forms, 
pyrochlore (Na, Cah Cb^O, OH, F>7 and columbite 6 (Fe, Mn) 
(Cb, Ta)20 6 . Mill concentrates produced from either mineral 
form contain approximately 60 pet columbium pentoxide 
(CD2O5), equivalent to about 42 pet Cb (2). Columbium con- 
centrates are principally recovered from pyrochlore 
minerals and, to a lesser extent, from columbite minerals. 
The most common upgraded form of columbium produced 
from pyrochlore concentrates is steelmaking-grade fer- 
rocolumbium. Recently, technology has been developed to 
convert this ferrocolumbium to columbium oxide suitable 
for the manufacture of high-purity ferrocolumbium, nickel- 



3 Information on columbium resources located in the U.S.S.R. or other cen- 
trally planned economy countries (CPEC's) is not available and is not ad- 
dressed in this evaluation. 

4 Italic numbers in parentheses refer to items in the list of references at the 
end of this report. 

6 Columbite is the columbium-rich member of the columbite-tantalite 
isomorphous series. 



columbium, and columbium metal (2). Prior to this 
technology, production of high-purity oxides was possible 
only through the processing of columbite ores. This develop- 
ment has greatly increased the market importance of 
pyrochlore ores. 

The purpose of this study is to evaluate columbium 
resources of the MEC and to assess the production costs of 
recovering ferrocolumbium. Table 1 lists 19 columbium 
deposits in 7 MEC's included in this study; figure 1 shows 
their locations. The majority of MEC columbium resources 
are found in Brazil and Canada. 

The United States is a major consumer of columbium 
products, totally dependent upon foreign sources for all of 
its columbium. More importantly, the U.S. ferrocolumbium 
industry could be threatened by the tendency of major col- 
umbium mine owners to further vertically integrate their 
operations to produce upgraded columbium products. If 
these producers were to supply upgraded columbium prod- 
ucts at significantly lower costs, the U.S. columbium in- 
dustry could be at a distinct economic disadvantage. Subse- 
quently, if the United States lost a major share of its proc- 
essing capability because of increased competition from 
abroad, it would become totally dependent upon imports for 
both columbium concentrates and upgraded columbium 
products (2). 



ACKNOWLEDGMENTS 



The authors would like to thank Larry D. Cunningham, 
Columbium Specialist of the Bureau's Division of Ferrous 



Metals in Washington, DC, for his assistance in the review 
of the data used in this report. 



Table 1.— Columbium deposit ownership and status data 



Nation and deposit name 



Owner 



Status' 



United States: 

Gem Park Complex' 

Iron Hill 2 

Brazil: 

Araxa 

Catalao 

Catalao Ouvidor . . . 
Canada: 

Crevier 

James Bay 

Lackner Lake 

Martison Lake 

Nemegosenda .... 

Niobec 

Oka 

Strange Lake 

Thor Lake 

Kenya: MrimaHill 

Tanzania: Panda Hill . 
Uganda: Sukulu Hills . 
Zaire: 

Bingo 

Lueshe 



Coca Mines, Inc 

Buttes Gas and Oil Co. 



CBMM 

Mineracao Cataloa de Goias S.A. 
Goias Niobio S.A 



SOQUEM 

Esso, Morrison, Canray, Argor 

Mertec Resources Develop Ltd 

New Venture Equities/Cambell Resources 

Gulf Agric Chem. Co. Ltd 

Teck Corp., SOQUEM 

St. Lawrence CB, Metals Corp 

Iron Ore Co. of Canada 

Highwood Resc, Calabros Ltd 

Mnma Industrial Minerals 

State Mining Corp. (STAMICO) 

Sukula Mines Limited 



Somikivu 
. . do ... 



NP 
NP 

P 
D 
P 

NP 
NP 
NP 
NP 
NP 
P 
NP 
NP 
NP 
NP 
NP 
NP 

NP 
NP 



'P producing. 
'Colorado. 



D Developing. NP Nonproducing. 



COLUMBIUM INDUSTRY 



Columbium serves as an alloying element in high- 
strength, low-alloy (HSLA) steels and superalloys. HSLA's 
are so named because of their relatively high strengths, ob- 
tained by the addition of very modest amounts of alloying 
elements (less than 1 pet alloying, other than carbon and 
manganese). This strengthening effect has led to wide- 
spread use of HSLA steels in oil and gas pipeline steels, in 
lighter, more fuel-efficient automobiles, and in the construc- 
tion of massive structures such as skyscrapers, bridges, and 
nuclear reactors (3). Columbium is also used as a "carbide 



stabilizer" in stainless steels to improve their resistance to 
corrosion when used in exhaust manifolds, fire walls, and 
pressure vessels. 

Cobalt-, nickel- and iron-based superalloys, containing 
between 1.0 to 5.0 pet Cb, are used to make gas-turbine 
engine components, rocket-nozzle subassemblies, and heat- 
resistant combustion equipment. 

New applications of columbium-containing supercon- 
ductors are being tested for future energy generation and 
transmission needs (2). Superconductors have the ability to 




Gam Park Complex 
Iron Hill 
Araxa 
Catalao 

Cotolao Ouvidor 
Crtvitr 
Jomts Bay 
Lackntr Lakt 
Morrison Lakt 
Ntmagottnda 



Niobec 
Oka 

Strangt Lakt 
Thor Lakt 
Mrimo Hill 
Panda Hill 
Sukulu Hills 
Bingo 
Lutsht 



FIGURE 1.— Location of MEC pyrochlore deposits. 



lose all resistance to direct electrical current at 
temperatures near absolute zero (3), and columbium has 
unrivaled properties of superconductivity relative to other 
pure metals. Therefore, most commercial superconductor 
devices use columbium alloys such as columbium-titanium 
(CbTi) or columbium-tin (CbsSn). 

The majority of columbium concentrates are derived 
from the beneficiation of pyrochlore ores. Columbite ores, 
including columbite and columbite-tantalite mineral ores, 
were once the primary source of columbium, but their 
significance has diminished in recent years. Advances in 
technology have made possible the production of high-purity 
oxides through further processing of ferrocolumbium pro- 
duced from pyrochlore concentrates (2). Previously, colum- 
bite ores were the major source of the oxides necessary for 
columbium-based alloys and superalloys. New technology, 
combined with the immense resource of pyrochlore ores, has 
almost totally replaced the use of columbite minerals as a 
source of columbium. 

Brazil is the world's largest producer and processor of col- 
umbium (fig. 2), most of which is recovered from two 
pyrochlore deposits. 6 

The pyrochlore deposit at Araxa, owned by Campanhia 
Brasileira de Metalurgia e Mineracao (CBMM), has been in 
operation since 1961 and is the world's largest known col- 
umbium deposit. CBMM is owned by Campanhia 
Metropolitana de Comercio e Participacoes (55 pet) and 
Molycorp Inc. (a subsidiary of Union Oil Co. of California) of 
the United States (45 pet). Brazil's other operating 
pyrochlore mine, located at Catalao and owned by 
Mineracao Catalao de Goias S.A. (MCG), began operation in 
1976. A 70-pct share of MCG was purchased by the Anglo- 
American Group in November 1984, with the balance (30 
pet) held by Unamina, a local group of investors. Develop- 
ment of a third pyrochlore mine, Catalao Ouvidor, began in 

1981. This deposit is owned by Goias Niobio S.A., and was 
tentatively slated to begin production in 1985. Partners of 
Goias Niobio S.A. include Produtos Metallurgico S.A. (51 
pet), Metais de Goais (24 pet), and Fibase, a subsidiary of 
National Economic Development Bank (25 pet). 

The majority of Brazilian mine production concerns the 
manufacture of steelmaking-grade ferrocolumbium. By 
1980, Araxa had vertically integrated its operation to in- 
clude production of high-grade columbium oxides and by 

1982, it had discontinued exporting pyrochlore concentrates 

(4). 

Canada is the second largest MEC producer and its only 
exporter of pyrochlore concentrates. The Niobec Mine, 
located near the town of St. Honore in Quebec Province, has 
been Canada's only operating pyrochlore mine since it began 
production in 1976. Ownership of Niobec is split evenly be- 
tween Societe Quebecoise d'Exploration Miniere 
(SOQUEM, a corporation of the Quebec Provincial Govern- 
ment) and Teck Corporation. The Oka Mine, also in Quebec, 
is owned by the St. Lawrence Columbium & Metal Corp. It 
began operation in 1961 but was closed in 1976 because of 
labor and economic problems. Substantial reserves remain 
at Oka and are included in this evaluation. 

Owners of the Leushe deposit in Zaire completed con- 
struction of a 2 mt/h pilot plant in March 1984. The pilot 
plant was set up by a joint venture of Sovaikubi (Societe 
Miniere Zairoise de Nyamukubi), Coframines, and 
Metallurg Inc. Commercial production is expected to begin 



6 Less than 1 pet of the columbium mined in Brazil is recovered as columbite 
from pegmatite mines that were not examined in this study. 



Others 
3 pet 




Total, 8,471 mt (Contained Cb) 
FIGURE 2.— Estimated MEC mine production, 1983. 

by the end of 1986 (5). The Leushe deposit is owned by 
Somikivu (Kivu Mining Co.) in which Metallurg holds a 
70-pct share, the Zaire Government 20 pet, and Sominki 
(Societe Miniere et Industrielle du Kivu) 10 pet. 

Columbium is considered a strategic and critical mineral 
to U.S. interests because of its defense-related uses in the 
aerospace, energy, and transportation industries. Colum- 
bium has not been mined commercially in the United States 
since 1959, except for small unreported quantities of 
columbium-bearing concentrates produced in 1980-82 (J+). 
Therefore, the United States is totally dependent upon 
foreign imports of columbium, primarily in the form of fer- 
rocolumbium or columbium oxides from Brazil and pyro- 
chlore concentrates from Canada. The United States im- 
ports smaller amounts of columbium in the form of colum- 
bite concentrates from Nigeria, tin slags from Malaysia and 
Thailand, and synthetic concentrates made by upgrading 
low-grade tin slags from the Federal Republic of Germany. 
Imports of columbite, especially from Nigeria, have been 
declining steadily. 

The U.S. columbium processing industry consists of eight 
companies with nine plants integrated through the process- 
ing of columbium concentrates to upgraded end products, 
including columbium metal (2). U.S. industry is potentially 
threatened by the continued vertical integration of foreign 
mines, principally in Brazil, through the production of high- 
grade columbium products. Brazil's share of the U.S. fer- 
rocolumbium market has increased from pet 20 yr ago, to 
nearly 75 pet (4). It is possible that this trend will lead to 
total U.S. dependence on foreign sources for all columbium 
products. 

Columbium stored in the National Defense Stockpile, as 
of November 30, 1984, amounts to 1,271 mt (2.8 M lb) con- 
tained columbium, primarily in the form of concentrate and 
ferrocolumbium, with smaller amounts contained in carbide 




Total, 10,340 mt 

FIGURE 3.— Estimated MEC ferrocolumblum production, 
1983. 



powder and columbium metal (4). The last sale from this 
stockpile was in 1976. In 1984, bids solicited by the General 
Services Administration to supply up to 400,000 lb of colum- 
bium contained in concentrates for the stockpile were re- 
jected because they were too expensive and did not conform 
to prevailing market conditions. (4). 

In 1983, MEC production of ferrocolumbium was 
estimated by the Bureau of Mines Columbium Specialist at 
10,340 mt (6). Figure 3 shows the breakdown of MEC fer- 
rocolumbium production by country and illustrates Brazil's 
control of an estimated 67 pet of the industry. Important 
amounts of ferrocolumbium are also produced using im- 
ported pyrochlore and columbite concentrates in the United 
States, Western Europe, and Japan. European producers of 
ferrocolumbium include Austria, Belgium-Luxembourg, the 
United Kingdom and the Federal Republic of Germany. The 
United States is currently the largest producer of colum- 
bium metal. 

Overall U.S. consumption of columbium increased from 
2,600 mt in 1983 to 3,500 mt in 1984, owing to increased 
consumption by steel and automotive industries (4). This 
reverses the 30-pct decrease reported in overall U.S. con- 
sumption in 1982 from the record high established in 1981 



EVALUATION METHODOLOGY 



METHODOLOGY 

Data collected for this report are stored, retrieved, and 
analyzed in a computerized component of the Minerals 
Availability Program (MAP). Data for foreign mines and 
deposits used in the evaluation were collected by Pincock, 
Allen & Holt, Inc., under Bureau of Mines contract 
J0225022 (<?). Data for domestic deposits were collected by 
the Bureau's Intermountain Field Operations Center in 
Denver, CO. After a deposit was selected for the analysis, 
an evaluation of the operation began. The flow of the 
Minerals Availability evaluation process from deposit iden- 
tification through analysis of availability information is il- 
lustrated in figure 4. The following evaluation and analysis 
methodology was used in this study: 

1. The quantity and grade of columbium resources from 
each deposit were evaluated in relation to physical and 
technological conditions affecting production as of the study 
date, January 1984. 

2. Actual mining, concentrating, and processing 
(smelting) methods employed at producing mines, along 
with appropriate methods used at nonproducers, were de- 
scribed. Related capital investments and operating costs for 
each operation were then estimated in 1984 dollars. 

3. An economic analysis of each operation was per- 
formed to determine: (a) the average total production cost 
at a specified discounted cash flow rate of return (DCFROR) 
on invested capital for each operation over its entire produc- 
ing life and (b) the ferrocolumbium potentially recoverable 
on a total and annual basis. 

4. Following individual property analysis, all properties 
in the study were aggregated into columbium availability 
curves. These curves represent total potential columbium 
contained in ferrocolumbium producible over the life of each 
operation, arranged in order from the lowest to highest cost 



deposits. The curves illustrate the comparative costs 
associated with any given level of potential total output, and 
provide an estimate of what the average long-run fer- 
rocolumbium price (in January 1984 dollars) would have to 
be for a given tonnage to become potentially available. This 
long-run price would provide enough revenue to cover the 
average total cost of production including an investment 
return high enough to attract new capital. A 15-pct real 
DCFROR on the total investment of each operation was 
used in this study. Additional curves were generated at a 
break-even or 0-pct DCFROR. 

5. Annual availability curves are also presented in the 
report. These curves show amounts of columbium potential- 
ly available each year at various levels of average total cost 
of production. These curves reflect the current installed 
capacity levels of producing deposits, including known ex- 
pansion and development plans, and assumed capacity 
levels and development schedules of undeveloped deposits. 

DEPOSIT SELECTION CRITERIA 

Deposit selection criteria was limited to known deposits 
with demonstrated resources of columbium. Ownership and 
current status information of individual columbium mines 
and deposits in this study are presented in table 1. 

For the 19 deposits evaluated, tonnage estimates were 
based on resource values considered demonstrated accord- 
ing to definitions established by the Bureau of Mines and the 
U.S. Geological Survey (9) (fig. 5). Demonstrated resource 
data presented in this paper were available from published 
sources (Bureau, U.S. Geological Survey, State and in- 
dustry publications, professional journals, and company an- 
nuals reports and lOK's), and personal contacts (deposit 
owners, individuals or government agencies with personal 
knowledge of the deposit). 



Identification 

and 

selection 

ot deposits 



Tonnage 

and grade 

determination 



Engineering 
and coat 
evaluation 



" Mineral 

Industries 

Location 

System 

(MILS) 

data 



MAP 

computer 

data 

base 



Deposit 

report 

preparation 



MAP 

permanent 

deposit 

files 



Data 

selection and 
validation 



Taxea. 

royalties. 

coat indexes, 

prices, etc... 



Economic 
analysis 



Data 



Availability I 
curves 



Analytical 
reports 



J 



Variable and 

parameter 

adjustments 



Sensitivity 
analysis 




JhJ 



Data 



Availability 
curves 



Analytical 
reports 



FIGURE 4.— Flow chart ol evaluation procedure. 



Cumulative 
production 



IDENTIFIED RESOURCES 



Demonstrated 



Measured Indicated 



Inferred 



UNDISCOVERED RESOURCES 



Hypothetical 



Probability range 
(or) 



Speculative 



ECONOMIC 



MARGINALLY 
ECONOMIC 



SUB- 
ECONOMIC 



Reserve 



base 



Inferred 



reserve 



base 



+ 



-1- 



Other 
occurrences 



Includes nonconventional and low-grade materials 



FIGURE 5.— Mineral resource classification categories. 



Resources for analysis had to be recoverable using cur- 
rent mining, milling, and processing technologies. In addi- 
tion, the deposits had to meet the following criteria: 

1. Producing properties included must account for at 
least 85 pet of the columbium production from each signifi- 
cant producing country. 

2. Developing and explored deposits and past producing 
deposits needed a demonstrated columbium reserve- 
resource quantity equivalent to at least the lower limits of 
the reserve-resource quantity of the producing deposits. In- 
ferred or hypothetical resource levels could not be included 
in the economic evaluations. 



3. Columbium produced as a byproduct of tin mining 
operations, such as in Nigeria, Thailand, and Malaysia* 
totals less than 5 pet of current world's production figures 
and was not included in this evaluation. 

For this study, a total of 3 producing mines, 1 develop- 
ing mine, and 15 nonproducing deposits were evaluated. All 
deposits evaluated in the study are from MEC's Information 
on columbium resources in CPEC's such as U.S.S.R. and 
China was not available. Additionally, properties at which 
columbium is produced as a byproduct of tin mining are not 
addressed in this evaluation. 



RESOURCES 



Estimates of in situ demonstrated resources amount to 
over 946 Mmt of material (5.36 Mmt of contained Cb) from 
studied deposits in the Western Hemisphere countries of 
the United States, Canada, and Brazil (collectively referred 
to in this study as the Americas), and the four African na- 
tions of Zaire, Uganda, Tanzania, and Kenya. A detailed 
breakdown of MEC resources is given in table 2 and figure 
6. Inferred resources from studied deposits contribute an 
additional 655 Mmt of material, containing 6.41 Mmt Cb. 
Approximately 79 pet of the inferred resources of contained 
Cb are found in Brazil, with Africa and North America con- 
taining 10 and 11 pet, respectively. 

Regionally, carbonite deposits in Brazil account for 60 
pet of the contained columbium resources at the 
demonstrated level. Another 26 pet is located in the United 
States and Canada with the remaining 14 pet found in the 
four African countries. Thus, 86 pet of these columbium 
resources are available in the Americas alone. 

Reserve base figures reported by the Bureau's columbium 
specialist (2, 4) were based largely on the data in this report. 
The following figures represent contained columbium: 

Brazil 3.6 Mmt 

North America: 

United States Negligible 

Canada 0.3 Mmt 

Africa 0.2 Mmt 



Differences in Brazilian resource tonnages reported by 
the columbium specialist and those reported here resulted 
from rounding up of the figures (by the columbium 
specialist) from 7.5 to 8.0 billion lb of contained columbium. 
The differences in resource tonnages reported for Canada 
and Africa resulted from exclusion of several deposits based 
on the columbium specialist's judgmental interpretation of 
their current economic feasibility. 



Table 2.— Summary of columbium resources In 
market economy countries 

In situ, Av grade Contained 
Mmt Cb, pet Cb, Mmt 

Demonstrated: 

Brazil 207 1.57 3.25 

North America 472 .29 1.37 

Africa 268 .28 .75 

Total 946 57 5.36 

Inferred: 

Brazil 290 1.75 5.08 

North America 250 .28 .70 

Africa 115 52 .60 

Total 655 57 6.38 

NOTE.— Data may not add to totals shown because of independent 
rounding. 





In situ, 946 Mmt Contained, 5.36 Mmt 

FIGURE 6.— Demonstrated columbium resources. 



GEOLOGY 



Columbium minerals chiefly occur in nature as oxides, 
multiple oxides, and hydroxides (10). Principal ore minerals 
include: 

Pyrochlore (Na, Ca)z Cl^ (0, OH, F^ 
Pandaite (Ba, Sr) (Cb, T) (0, Orfy 
Columbite-tantalite (Fe, Mn) (Cb, Ta)A 
Loparite (Ce, Na, Ca^ (Ti, CbJA 
Ixiolite (Ta, Nb, Sn, Fe, Mn) 4 8 

Economic concentrations of columbium minerals occur 
predominantly in the following related members of intrusive 
alkaline rock complexes: 

a. carbonatites. 

b. alkaline granites. 

c. pegmatites. 

d. nepheline syenites. 

Alkalic rock complexes are commonly restricted to the 
stable Precambrian cratons of continents (11). These com- 
plexes are often found in spatial relationship with fault 
lineaments such as the Kapuskasing-Moosonee High and the 
St. Lawrence River Fault in Canada, and the marginal fault 
of the East African rift system (12). However, some occur- 
rences are less obvious where the spatial relationship may 
not in fact exist. Alkaline complexes commonly occur as 
small circular or elliptical bodies (usually less than 5 miles in 
diameter), arcuafe ringlike structures, cone sheets, or 
crosscutting dikes. 

Carbonatites provide the overwhelming source of colum- 
bium in the world. In fact, all current producers included in 
this study recover columbium from carbonatites. Car- 
bonatites usually occur central to the alkaline complex in the 
form of a plug or an irregularly shaped body up to 3 mi 2 in 
area, or as a crosscutting dike (13). 

Carbonatites are chemically unique igneous rocks that 
contain an anomalous amount of carbonates and resemble 
marble (13). The majority show an excess of calcite and are 
called sovites; those dominated by magnesium carbonates 
are called ankerites. Pyrochlore characteristically reaches 
peak abundance in sovites, though it has been reported in 
practically all associated rock types of the alkaline granitic 
suite (12). In addition, carbonatites may contain significant 
concentrations of phosphate, titanium, rare earths, 
uranium, thorium, fluorite ore minerals, and others. 

The combination of radioactive thorium and uranium has 
greatly aided in the discovery of carbonatites. Radiometric 
reconnaissance using a gamma ray scintillometer was in- 
strumental in discovering the Niobec property. Mag- 
netometer surveys have also proven useful in the discovery 
of carbonatites enriched in magnetite. 

Pyrochlore minerals predominantly occur in either 
primary or secondary carbonatites. Primary deposits repre- 



sent the hard-rock ore body usually found in more 
temperate climates in which weathering has not been 
significant. Columbium is manifested as pyrochlore and con- 
centrations range from 0.5 to 0.7 pet. The Niobec and Oka 
deposits in Canada are examples of this type. 

Secondary deposits are found typically in tropical regions 
characterized by abundant rainfall. Deep in situ weathering 
results in strong residual enrichment of the more resistant 
columbium, phosphate, and iron minerals (14). Under these 
conditions, columbium may occur in an altered mineral form 
of pyrochlore called pandaite (more correctly known as 
bariopyrochlore) in which the sodium and calcium ions are 
replaced in varying percentages by barium and/or stron- 
tium. Enrichment of the columbium ore is 2 to 10 times 
greater than the concentrations found in primary deposits. 
The highest concentration of columbium ore is in the elluvial 
or laterized material which forms a cap overlying the car- 
bonatite body. All Brazilian deposits have undergone this 
columbium enrichment process. African deposits, expecially 
the Zairian, have undergone similar enrichment, but to a 
lesser extent. The importance of this grade enrichment 
becomes most obvious when comparing in situ dem- 
onstrated resources to the contained columbium. Figure 6 
shows that Brazil, which contains 22 pet of the studied in 
situ demonstrated resources, actually possesses 60 pet of 
the studied contained columbium. 

Alkaline granites and related ultramafics are a potential 
source of columbium in Canada. Deposits apparently 
associated with later stages of the alkaline intrusive event 
characteristically contain higher concentrations of tantalum 
in the columbite-tantalite minerals. If this tantalum can be 
economically recovered, alkaline granites might become 
significant sources of tantalum as well as columbium. 
Crevier and Thor Lake are examples of such deposits. 

Pegmatites and their respective placer deposits once 
served as the major source of columbium in the mineral 
columbite-tantalite. Columbium was often produced as a 
coproduct with tantalum, both of which are byproducts of 
tin mining. The Jos Plateau in Nigeria is an example of such 
an operation (a tin mine producing byproducts of columbium 
and tantalum). The importance of columbite as a source of 
columbium has diminished in recent years with the in- 
creased utilization of pyrochlore ores. As such, pegmatites 
and their respective placer deposits currently contribute 
less than 5 pet of the MEC supply of columbium and are not 
included in this study. 

Columbium deposits in the U.S.S.R. are principally de- 
rived from nepheline syenites, which comprise 1 pet of the 
exposed rock in that country. The main area of concentra- 
tion is on the Kola Peninsula. The principal columbium 
mineral is loparite, which contains approximately 12 pet 
(Nb.Ta^Oe (10-11). 



MINING AND PROCESSING OF COLUMBIUM 



MINING METHODS 

All but 2 of the 19 columbium properties examined in this 
study are amenable to open-pit mining techniques. Of the 
three producing properties, Niobec is the only underground 
operation. Open-pit mining is performed at both Araxa and 



Catalao and is proposed for use in development of the 
Catalao Ouvidor deposit. Because of the highly weathered 
nature of the ore at these three operations, blasting is not 
required, allowing actual mine recoveries to exceed 90 pet. 
Ore material is mined using crawler tractors and loaded by 
front-end loaders onto either conveyor systems (used at 



Araxa) or trucks (used at Catalao) to facilitate haulage to 
the mill. At Catalao, various degrees of weathering have 
resulted in inconsistent ore grades throughout the deposit. 
Drilling and metallurgical tests of drill-hole samples are re- 
quired to determine ore grade in advance of mining. The ore 
is stockpiled according to grade and blended prior to 
beneficiation to achieve a constant feed grade. 

Drilling and blasting have been proposed for the Canadian 
depoists because of their hard-rock ore bodies. Blasting is 
expected to require over 300 g of explosives per metric ton 
of material. 

African deposits, though highly weathered, will require 
blasting to fracture the more resistant zones estimated to 
occupy 10 to 20 pet of each ore body. This blasting is 
estimated to require approximately 200 g of explosives for 
each metric ton of material mined. Expected mine 
recoveries range between 85 and 95 pet of the Canadian and 
African deposits. 

Underground mining at Niobec is accomplished using a 
large-diameter blasthole stoping method. Mine development 
extends to a depth of 402 m and is serviced by a timbered 
shaft. Development levels are situated at 91, 137, 229, and 
259 m. Primary crushing is carried out underground at the 
350-m level. Mechanized, trackless mining equipment is 
used for the extraction of ore from the large vertical stopes. 
Mining equipment includes jumbos used to drive most 
headings, scissor lifts for rock bolting, and a combination of 
trucks and scooptrams (diesel and electric) for mucking. 
During stoping, in-the-hole drill rigs perform the drilling. 
Blasting of the bedrock requires a powder factor of 300 g of 
explosives per metric ton of material. 

Sublevel stoping is proposed to replace surface mining in 
the Leushe deposit in Zaire after the sixth year of produc- 
tion. Underground haulage would be accomplished using 
trackless equipment. Jumbos would be used to drive the 
sublevel drifts. Blasting is expected to require 360 g of ex- 
plosives per metric ton of material mined. 



Magnetic separation is not carried out at every operation 
and may serve different purposes when used. Deposits with 
high magnetite concentrations like Araxa and Catalao use 
magnetic separation to remove the magnetite, which can 
amount to as much as 25 pet of the ore. This magnetite is ap- 
proximately 67 pet Fe and is stockpiled for potential future 
recovery of the contained iron (74). Magnetic separation 
may also be used to concentrate the slightly magnetic 
pyrochlore ore. This process usually precedes desliming at 
most operations; however at Niobec, this step follows the 
desliming and the carbonate and pyrochlore flotation cir- 
cuits. 

During pyrochlore concentration, the desliming circuit is 
considered the most critical stage. Large quantities of 
slimes may inhibit the recovery of columbium as a 
pyrochlore flotation concentrate. Therefore, a three-stage 
desliming circuit is used, consisting of various sized 
classification and desliming cyclones along with scrubbers. 
Three desliming products are discharged from this circuit: a 
coarse fraction (greater than 30-/xm), a slime fraction (be- 
tween 3 and 30/*m) and a tails fraction. At Araxa, colum- 
bium is concentrated in the minus 37- + 5-/im fraction. A 
minus 5-^m split eliminates 12 pet of the slimes, but only 5 to 
7 pet of the columbium (14). 

The columbium mineral is recovered by selective froth 
flotation of the pyrochlore. If coarse and slime products of 
desliming are discharged, a separate circuit is used for the 
flotation of fine particles from the desliming cyclones. 
Niobec uses a carbonate flotation circuit prior to pyrochlore 
flotation. Conditioning of the pyrochlore concentrate takes 
place in the desliming stage or just prior to flotation in a 
separate conditioning stage. Each flotation section consists 
of one rougher stage followed by three to five stages of 
cleaners. Final pyrochlore concentrates from both sections 
are combined and sent to thickening and filtration prior to 
calcining and leaching. The Niobec pyrochlore concentrate 
is not leached; instead it is sent to a sulfide flotation circuit 
to remove pyrite (fig. 7). 



BENEFICIATION METHODS 

Current columbium producers use a milling process to 
concentrate pyrochlore. This process includes crushing and 
grinding, magnetic separation, desliming, flotation, 
leaching, and calcining. An idealized mill process flow 
diagram is shown in figure 7. Most of the nonproducing 
properties included in the study were evaluated based on 
similar flowsheets, with some modifications due to ore 
metallurgy. Mill recoveries ranged from 20 to 80 pet based 
on variations in feed grade and physical characteristics of 
the ore (including fine-ness of pyrochlore minerals and the 
presence of impurities). 

Depending on the type of ore, one to three stages of 
crushing are necessary. Laterized ores, such as Araxa's re- 
quire less crushing than hard-rock ores, such as Niobec's. 
Crushing circuits consist of various vibrating screens, which 
feed jaw and impact crushers in open or closed circuits. 
Crushing circuit output ranges from minus 10 to minus 50 
mm depending on optimum pyrochlore crystal liberation 
size. 

Ball and rod mills are used in the grinding circuit, usually 
in one or two stages, to reduce the ore to optimum liberation 
size. Araxa pyrochlore is very fine grained with the majority 
of crystals smaller than 1 mm. Optimal liberation requires 
grinding 95 pet to minus 104 /xm (minus 150 mesh) (U). This 
product is then sent through magnetic separation. 



Crushing and screening 



Tailings » — 



(NIOBEC) 



Desliming -« 

I 

Carbonate 



Sieving and grinding 



Magnetic separation 



Nonmagnetic* 



Desliming 



•Magnetic tailings 
(stockpiled) 



Tailings 



Tailings •* . 



- Tailings 



Calcining and leaching » Tailings 



, Tailings 
pond 



Columbium concentrates 



Ferrocoiumoiam plant 



FIGURE 7.— Typical process flowsheet for pyrochlore mill. 



10 



A calcining and leaching stage may be necessary to reduce 
high concentrations of phosphate to meet market specifica- 
tions. This is the situation at the Brazilian mines where two 
stages of leaching are used; a HC1 acid leach and a NaOH 
leach. At Araxa, pyrochlore is calcined prior to the leaching 
steps, while at Catalao, calcining follows both leaching 
steps. 

SMELTING METHODS 

Aluminothermy is a batch process used for producing fer- 
rocolumbium from pyrochlore concentrates. A typical reac- 
tion charge at CBMM's Araxa ferrocolumbium operation as 
reported by de Souza Paraiso and de Fuccio (U) follows: 

Pyrochlore concentrate (60 pet Ct^C^) . . 18,000 kg 

Iron oxide (as hematite) (68 pet Fe) 4,000 kg 

Aluminum powder 6,000 kg 

Fluorspar 750 kg 

Lime 500 kg 

This charge is thoroughly mixed and then poured into a 
magnesite-brick-lined, steel cylinder. This cylinder, or reac- 
tor vessel, is placed into a silica sand bed lined with a mix- 



ture of lime and fluorspar. A fuse mixture of aluminum 
powder and barium or sodium peroxide, ignited by a flame 
or small quantity of water, is used to start the exothermic 
reduction. Reaction time lasts 15 to 20 minutes and reaches 
a maximum temperature of 2,400°C. During this reaction, 
gangue material, along with other impurities forming the 
slag, separates from the columbium-iron alloy. After the 
reaction is completed and slag is drained off the top, the 
reaction cylinder is lifted, leaving columbium metal in the 
sand pit. After several hours of cooling and solidification, 
this metal "button" is removed from the pit, crushed, sieved, 
sized (depending on market specifications), and packaged 
for shipping. A typical charge will produce approximately 
11 mt of ferrocolumbium containing 66 pet Cb (l\). A similar 
grade of ferrocolumbium is produced at the Catalao smelter 
and expected from the developing Catalao Ouvidor opera- 
tion. 

A ferrocolumbium smelter costing model was developed 
by Pincock, Allen & Holt, Inc. (8) for the Niobec Mine and 
subsequently applied to all nonproducing deposits for 
costing purposes. The model is very similar to the 
aluminothermic process used by the Brazilian operation ex- 
cept that it produces a ferrocolumbium product containing 
60 pet Cb. 



COLUMBIUM DEPOSIT COSTS AND EVALUATION 



COSTING METHODOLOGY 

For each property included in this study, a capital and 
operating cost evaluation was made, to reflect (as nearly as 
possible) actual operations or, in the case of nonproducers, 
to reflect expected operational technologies and capacities. 
Costs for U.S. deposits were developed by the Bureau's In- 
termountain Field Operations Center, Denver, CO, based 
either (1) on actual reported company data, (2) scaling from 
similar known operations, or (3) using the Bureau's Cost 
Estimating System (CES) (25). Costs from all foreign 
deposits were collected and developed by Pincock, Allen & 
Holt, Inc. (8). Some of the foreign deposits costs were actual 
company reported data; others were contractor estimates. 

All costs presented in this report are in terms of January 
1984 U.S. dollars, using appropriate exchange rates. The 
cost estimates reflect a prefeasibility estimate of ± 25 pet. 

Capital expenditures were calculated for exploration, ac- 
quisition, development, mine plant and equipment, con- 
struction of the mill plant, and installation of the mill equip- 
ment. Capital expenditures for mining and processing 
facilities include the costs of mobile and stationary equip- 
ment, engineering design, facilities and utilities, and work- 
ing capital. Facilities and utilities (infrastructure) includes 
the cost of access and haulage facilities, water facilities, 
power supply, and personnel accommodations. Working 
capital is a revolving cash fund required for such operating 
expenses as labor, supplies, taxes, and insurance. 

Mine and mill operating costs are calculated as a combina- 
tion of direct and indirect costs. Direct operating costs in- 
clude materials, utilities, direct and maintenance labor, and 
payroll overhead. Indirect operating costs include technical 
and clerical labor, administrative costs, facilities 
maintenance and supplies, and research. Other costs, not in- 
cluded in operating costs but used in the analysis, include 
depreciation, insurance and taxes, and royalties. Operating 



costs of ferrocolumbium plants and costs to transport the 
concentrates to the nearest plants were also included in this 
analysis. 



OPERATING COSTS 

Total operating costs are composed of mining, milling, 
and smelting costs; taxes (including property, state, 
Federal, and severance); and royalties. The percentages 
contributed to total operating cost by each principal 
operating component are shown in table 3 and figure 8. Ac- 
tual operating costs for producers (not reported to protect 
the confidentiality of information) are significantly less than 
those for nonproducers. Total operating costs for Canadian 
and African nonproducers have been estimated at $9.27 and 
$7.34, respectively, per pound of contained columbium in 
ferrocolumbium. 

For most of the examined properties, total operating 
costs decrease with increasing mill feed grades. Exceptions 
occur in cases where unique ore mineralogies do not permit 
efficient beneficiation. Table 3 shows feed grade as a 
weighted average calculated on a yearly production basis. 

For producing surface mines in Brazil, operating costs are 
greatest in the milling and smelting area because the highly 
laterized Brazilian ores do not require blasting and can easi- 
ly be mined at relatively low costs. Conversely, in Canada, 
mining costs estimated for nonproducing deposits include, 
blasting expenses required to fracture the hard-rock ore 
bodies and the more resistant, unweathered zones in the 
laterized African deposits. As expected for underground 
mines, mining costs comprise a major percentage of the 
total cost. Taxes and royalties are generally greater for non- 
producers in this study because of the increased revenues 
required to cover the higher overall costs (including profit). 
Nonproducers require a higher taxable income (leading to 



11 



TABLE 3.— Breakdown of operating cost expressed as a percentage of total costs 

Producers Nonproducers 

Brazil N. America N. America Africa 

(surface)' (underground) (surface) (surface) 1 

Feed grade" pet.. 1.40 0.47 0.27 0.65 

Ore capacity 4 mt/yr . . 9,240 3,406 2,430 2,275 

Total operating cost* W W $9.27 $7.34 

Operating cost, pet of total: 

Mining I 9 34 28 23 

Milling 36 26 35 32 

Taxes and royalties' 17 6 25 29 

Transportation 5 2 3 

Smelting 38 29 10 13 

Total 100 100 100 100 

W Information withheld to avoid disclosing individual deposit data. 
'Includes 2 producing and 1 developing mine In Brazil. 
a Leushe deposit is included as surface operation. 
'Weighted average of ore grade to mill based on yearly production. 
'Annual ore capacity as contained columbium. 

'All costs are expressed as January 1984 U.S. dollars per pound of columbium contained in ferrocolumbium product on a weight-averaged basis. 
'Includes all property, State, Federal, and severance taxes plus any royalty. The nonproducing deposits would require higher income in order to pro 
vide the stipulated 15-pct DCFROR; thus, aggregate tax payments are generally higher than for producing mines. 



o 



o 

Q. 



I- 

o 
o 



cr 

UJ 

rx 
o 




Producers 

Brazil 
(surface) 



Producers 

North America 

(underground) 



Nonproducers 

North America 

(surface) 



Nonproducers 

Africa 

(surface) 



FIGURE 8.— Operating cost comparison for columbium 
mines and deposits. 



12 



TABLE 4.— Mine, mill, and smelter operating cost by 
principal component, percent 

I ,K«r Dor+o C..=l BlaStillfl M&- EI6C- 

Labor Parts Fuel powde ? ter i a | trlcal 

PRODUCERS' 

Surface: 

Mine 70 15 15 1 NAp NAp 

Mill 37 10 11 NAp 15 27 

Smelter 13 2 1 NAp 83 1 

Underground: 

Mine 56 16 6 15 1 7 

Mill 37 21 2 NAp 31 9 

Smelter 11 3 NAp NAp 85 1_ 

NONPRODUCERS (SURFACE)' ' 

North America: 

Mine 60 20 6 6 7 1 

Mill 48 14 2 NAp 29 7 

Smelter 11 3 1 NAp 85 1 

Af rics* 

Mine 50 25 12 5 8 NAp 

Mill 43 15 1 NAp 25 16 

Smelter 11 3 1 NAp 85 1_ 

NAp Not applicable. 

'Includes 2 producing and 1 developing mine in Brazil. 

2 Leushe deposit is included as surface operation. 

NOTE— Data may not add to totals shown because of independent 
rounding. 

higher tax payments) to cover all operating costs and pro- 
vide a 15-pct DCFROR on all investments. Operating costs 
for all properties? except in Brazil, also include the cost of 
transporting concentrates to a ferrocolumbium smelter. 
Brazilian operations include a smelter on site. 

Mine, mill, and smelter operating costs for all studied 
deposits are broken down by percentage and shown in table 
4. Both mine and mill operating costs are shown to be heavi- 
ly weighted towards the cost of labor. Smelter costs are 
heavily weighted by the cost of industrial materials. This is 
directly related to the large quantities and high cost of 
aluminum used in the aluminothermic process. 

CAPITAL COSTS 

Table 5 and figure 9 show the average capital investments 
necessary to develop nonproducing columbium deposits in 
North America and Africa. For all deposits, mill in- 
vestments comprise the greatest share of total in- 
vestment- 61 pet for North American deposits and 65 pet 
for African deposits. This is expected since similar concen- 
trating processes are proposed for practically all operations. 
Notice the total capital cost is slightly less for the North 
American deposits, which have higher ore capacities. 



TABLE 5.— Breakdown of capital cost required to develop non- 
producing columbium deposits In North America and Africa 1 

North America Africa 

Av ore capacity per deposit 10 5 mt/yr.. 900 350 

Total capital (10« U.S.$) 59 26 

Annual capital costs, U.S.$/mt ore: 
Exploration, acquisition, development 

Mine 

Mill 

Total 66 74 

Cost item share of total investment, pet: 

Exploration, acquisition, development ... 16 8 

Mine 22 27 

Mill 61 65 

NOTE:— Data may not add to total shown because of independent 
rounding. 

'All deposits are anticipated to be surface mines. The Leushe deposit 
in Zaire is included as a surface mine although underground mining will 
begin following the 6th year of production. 



11 


6 


15 


20 


40 


48 




FIGURE 9.— Estimated capital cost required to develop 
nonproducing deposits. 

Capital costs for the nonproducers in both Canada and 
Africa primarily reflect equipment cost (60 to 65 pet). The 
remaining capital is split between the construction costs for 
materials and labor. 



COLUMBIUM AVAILABILITY 



ECONOMIC EVALUATION METHODOLOGY 

After establishing cost and engineering data, production 
parameters and cost estimates for each mine and deposit 
were entered into the Bureau's Supply Analysis Model 
(SAM). The Bureau has developed the SAM to perform 
DCFROR analyses to determine the long-run constant 
dollar price at which the primary commodity must be sold to 
recover all costs of production and investments (16). The 
DCFROR is defined as the rate of return making the pres- 



ent worth of after-tax cash flow from an investment equal to 
the present worth of all investments (17). For this study, a 
15-pct DCFROR was considered the necessary rate of 
return to cover the opportunity cost of capital plus risk. The 
determined value for columbium is equivalent to the 
average total cost of production (less credits for byproducts) 
for the operation over its producing life under the set of 
assumptions and conditions necessary to make an evalua- 
tion (e.g., mine plan, full-capacity production, and a market 
for all output). 



13 



If an operation has more than one product, each is priced 
according to the January 1984 market price. Revenues 
generated from each byproduct are credited to the proposed 
operations if, at the time of the study, their recovery was 
economically feasible. The following byproduct prices were 
used in this analysis: 

Market 
Byproducts price, $lmt 

Beryl ore 1,212.75 

Phosphate 18.00 

Rare-earth oxides 362.25 

Tantalum ^O.OO 

Contained. 

Potential byproducts for specific deposits are listed below: 

Deposit name Byproduct 

Canada: 

Crevier Tantalum. 

Martison Lake Phosphate. 

Strange Lake Beryl ore, rare earths. 

Thor Lake Tantalum. 

Uganda: Sukulu Hills Phosphate. 

None of the producing columbium mines in this study 
recover byproducts. 

Although tantalum is present in the Canadian Crevier and 
Thor Lake deposits, a mill concentrate of sufficient 
marketable Ta^ grade could not be produced to justify ap- 
plying a credit. An estimated minimum tantalum grade of 
20-pct Ta20 5 would be required to justify a credit. 

Based on the Bureau's methodology, all capital in- 
vestments incurred prior to January 1969 are presumed to 
be fully depreciated and are treated as sunk costs. Capital 
investments incurred since January 1969 have the 
estimated undepreciated balance carried forward to 
January 1984. All reinvestment, operating, and transporta- 
tion costs are expressed in January 1984 U.S. dollars. No 
escalation of either costs or prices was included because any 
increase in costs would be offset by an increase in market 
price of the commodities (16). 

Detailed cash-flow analyses were generated by the SAM 
i for each preproduction and production year of an operation 
beginning with the initial year of the analysis, 1984. Upon 
completion of the individual property analyses for each mine 
or deposit, all properties included in the study were 
simultaneously analyzed and aggregated into resource 
availability curves. Two types of curves have been 
generated for this study: (1) total availability curves at a 
15-pct and 0-pct DCFROR, and (2) annual curves at selected 
production costs. Potential tonnage and estimated average 
total cost for each mine and deposit evaluated have been ag- 
gregated into columbium availability curves to illustrate the 
comparative costs associated with any given level of poten- 
tial total output. 

Total resource availability curves show the total quantity 
of recoverable columbium potentially available at each 
operation's average total cost of production (less byproduct 
credits) over the life of the mine, determined at the 
stipulated (15-pct) DCFROR. Thus, the curve shows an ag- 
gregation of the total potential quantity of columbium pro- 
ducible over the life of each operation, ordered from opera- 
tions with the lowest to highest average total cost of produc- 
tion. The curve provides a concise, easy-to-read, graphic 



analysis of the comparative costs associated with any given 
level of potential output and provides an estimate of what 
the average long run price of columbium (in January 1984 
dollars) would have to be for a given tonnage to be potential- 
ly available to the marketplace. 

Annual curves are simply a disaggregation of the total 
curve to show annual columbium availability at varying 
costs of production. Each curve represents an amount of 
material potentially available annually at, or below, a 
specific cost level. The horizontal axis represents time, in 
either actual years (for producers) or the number of years 
following the commencement of development (for non- 
producers.) The vertical axis represents annual production 
levels based upon an aggregation of proposed capacities of 
each property within a specified cost range. 

Certain assumptions are inherent in all curves. First, each 
deposit produces at full operating capacity throughout its 
productive life. Second, each operation is able to sell all of 
its byproducts at the market prices and all of its primary 
products at a price sufficient to generate total revenues 
equal to or greater than its average total production cost. 
Third, development of each nonproducing deposit is as- 
sumed to begin in the same base year (N) (unless the proper- 
ty was developing at the time of the evaluation). 

Since it is difficult to predict when the explored deposits 
ire going to be developed, an assumption is necessary to il- 
lustrate the maximum potential annual availability with 
minimum lag time. It is doubtful that this potential would be 
reached in the short term since it is unlikely all non- 
producers would start preproduction in the same year. The 
preproduction period allows for only the minimum engineer- 
ing and construction period necessary to initiate production 
under the proposed development plan. Consequently, the 
additional time lags and potential costs involved in filing for 
and receiving required permits, financing, etc., have not 
been included in the individual deposit analyses. 



TOTAL AVAILABILITY 

Nineteen columbium deposits located in the United 
States, Brazil, Canada, Zaire, Uganda, Tanzania, and 
Kenya are included in the evaluation of MEC total 
recoverable columbium resources. These properties contain 
a total of 5.36 Mmt Cb in demonstrated resources; at an 
average recovery rate of 65 pet, a total of 3.47 Mmt is 
recoverable. The Bureau of Mines estimates that up to 90 
pet of the columbium recovered is consumed by the 
steelmaking industry in the form of ferrocolumbium (1). For 
this study, it is assumed that all (100 pet) of the columbium 
recovered goes to the production of ferrocolumbium. 
Therefore, using an average grade of 64-pct Cb contained in 
ferrocolumbium, a total of 5.42 Mmt of ferrocolumbium is 
potentially available from the 19 deposits. 

Table 6 and figure 10 clearly show Brazil as the MEC 
largest potential source of recoverable columbium, contain- 
ing 2.39 Mmt or 69 pet of the studied total recoverable co- 
lumbium. In addition, recent reports have claimed discovery 
of a columbium deposit at Seis Lagos, in the Amazon region, 
which could contain 38 Mmt of ore containing as much as 
1.75 pet Cb (18, 19). 

North America accounts for 11 of the 19 deposits 
evaluated, which amounts to 21.7 pet or 0.75 Mmt of the 
MEC total recoverable columbium resources. Combined 
with resources of Brazil, the Americas resources total 3.14 



14! 



TABLE 6.— Total recoverable tonnage of columbium and 
ferrocolumblum 

Total recoverable Total ferro- Av Cb 
columbium, 10* mt columbium, 10* mt content, pet 



Brazil 

North America 
Africa 



2.39 
.75 
.33 



3.62 

1.25 

.55 



65.9 
60.0 
60.0 



Total or wtd av 



3.47 



5.42 



64.0 



NOTE— Data may not add to totals shown because of independent 
rounding. 



Mmt of recoverable columbium or slightly less than 91"pct of 
studied MEC resources. 

African resources are all from five deposits, containing a 
total of 0.33 Mmt of recoverable columbium, accounting for 
the remaining 9 pet of MEC recoverable columbium. 

Figure 11 is a graphic representation of total availability 
of potentially recoverable columbium resources as related to 
total production cost. At a total cost (including a 15-pct 
DCFROR) of $5 and below, the curve is masked to insure 
the confidentiality of information concerning lower cost 
operations. 

At a cost of production comparable to the January 1984 
market price of $6/lb for columbium contained in fer- 
rocolumbium, slightly over 2.50 Mmt Cb is potentially 
available. This amounts to approximately 72 pet of studied 
recoverable resources. All producing deposits are capable of 
profitably operating below the market price. Present pro- 
ducers have recoverable columbium resources totaling 2.42 
Mmt or slightly less than 70 pet of the MEC resources. 

Cumulative MEC demand for columbium between the 
years 1981 to 2000 was estimated by the Bureau of Mines to 
be 415,000 mt (2). This estimate was based on an annual 
growth rate in the demand for columbium of 5.1 pet. 
Therefore, adequate supplies of columbium from currently 
producing mines should be available well beyond the year 
2000. According to the 1982 report of the National Research 
Council (20), the Araxa mine in Brazil contains sufficient 
resources to alone "supply world needs for decades if not 
centuries." 

At a total production cost comparable to doubling the 
market price to $12/lb, figure 11 shows only a 9.7-pct in- 
crease or 0.34 Mmt of additional recoverable columbium 
from studied properties. This means that most of the MEC 
known resources can economically be produced at, or below, 
the present market price. The abundance of low-cost colum- 
bium from producing mines might inhibit incentives to begin 
development of new mining projects targeting columbium. 

Figure 12 is a comparison between resources available in 
the Americas and the total recoverable resource from all 
studied deposits. The Americas total recoverable resource 
of 3.14 Mmt comprises over 90 pet of MEC potential 
resources. Brazilian resources alone total 76 pet of the total 
Americas resources or 2.39 Mmt recoverable columbium. 

At a cost of production comparable to the January 1984 
market price, approximately 78 pet (2.45 Mmt) of the 
Americas recoverable columbium resources are potentially 
available. In comparison to the MEC availability at this 
price, 97.8 pet is present in the Americas. At a total produc- 
tion cost comparable to double the market price, only an ad- 
ditional 10 pet would become available in the Americas, 
resulting in 2.73 Mmt of recoverable columbium. 

The difference between the Americas and the MEC total 
availability curve represents the four African nations con- 
tribution to MEC columbium resources. This difference in 




Total, 3.5 Mmt 

FIGURE 10.— Recoverable columbium from evaluated 
mines and deposits. 

total recoverable columbium availability at the maximum 
total cost (shown in figure 12) is 0.33 Mmt. 

The relationship between total cost and availability of 
recoverable columbium from nonproducers at both a 15- and 
a 0-pct DCFROR is shown in figure 13. Recoverable 
resources from studied nonproducers total 1.05 Mmt Cb of 
which 68 pet or 0.71 Mmt is located in the Americas. Fur- 
ther examination of the graph shows that at a cost of pro- 
duction comparable to the January 1984 market price 
($6/lb), only 0.08 Mmt are available assuming a 15-pct 
DCFROR. This is only 8 pet of total available resources 
from nonproducers and 2.4 pet of resources from all studied 
properties. At a cost level comparable to a doubling of the 
market price, an additional 0.34 Mmt of potentially 
recoverable columbium could be economically available. This 
amounts to 0.42 Mmt of recoverable columbium or 40 pet of 
the total available from nonproducers, but only 12 pet of 
that available from all studied deposits. 

Figure 13 compares the effect of imposing a 15-pct 
DCFROR as opposed to a 0-pct DCFROR (break-even cost) 
on the total cost of production for nonproducers. This com- 
parison is most relevant to deposits in which a 15-pct profit 
may not be a crucial factor for development. 

Figure 13 shows a majority of potentially recoverable col- 
umbium from nonproducers at the break-even level is 
available at costs between $6 and $11.50. Conversely, at the 
15-pct DCFROR, to produce the same amount of 
recoverable columbium involves costs of between $11.50 
and $19.50. Therefore, doubling the market price to cover 
the total cost of production up to $12/lb at the break-even 
level could result in the development and recovery of 1.02 
Mmt, or 97 pet, of available columbium from nonproducers. 

In summary, nonproducing columbium deposits have 
much lower total costs at the break-even level than at a 
specified 15-pct DCFROR. This fact may provide incentive 
for development of a columbium property assuming a situa- 
tion arises in which a 15-pct DCFROR is not pursued. 



115 



25 



20 



KEY 

Masked to protect confidentiality of 
information on lower cost operations 



J 



CO |i 



o 

~3 



CO 

o 
o 



10- 



f 




0.5 



1.0 1.5 2.0 2.5 

RECOVERABLE COLUMBIUM, Mmt 



3.0 



3.5 



FIGURE 11.— Total cost and total recoverable columblum 
from MEC mines and deposits. 



25 



20 



-w- 

CD l5 



c 
o 

~3 



CO 

° 10 
o 



o 



KEY 

Masked to protect confidentiality of 
information on lower cost operations 

Americas 
All deposits 



r~r J 




1.0 1.5 2.0 2.5 

RECOVERABLE COLUMBIUM, Mmt 

FIGURE 12.— Total cost and total recoverable columblum 
from Americas as compared with data for all selected 
deposits. 



3.5 



16 



25 



20- 



Z if 

0> 



to 
O 

o 

_) 
< 

o 



1 1 

KEY 


1 — ■ 


1 1 






ie _ nr+ nrrpop 














0-pctDCFROR 










~ 




i 


















i 


i 
i 




_, -"'"' 




i 




- 




i - 


i 








_j — ' 










i — ■ 
i 










1 






— 


J" 1 


■ 


i i 





10- 



5- 



0.2 



1.0 



0.4 0.6 0.8 

RECOVERABLE C0LUMBIUM, Mmt 
FIGURE 13.— Total cost and total recoverable columblum from nonproducers at 0- and 15-pct DCFR0R. 



I.2 



However, the dominance of the Brazilian and Canadian pro- 
ducers, in terms of low-cost levels and sizable resources 
would likely inhibit any such development even at the breaP 
even level. 



ANNUAL AVAILABILITY 

Annual availability curves portray the potential annaul 
availability of recoverable columbium contained in fer- 
rocolumbium within a specified range of total cost. Annual 
curves as presented assume each operation will produce at 
full capacity over its life and should not be interpreted as 
true supply curves. 

An annual availability curve for the three producing mines 
is presented in figure 14. At a total cost of less than $6/lb, 
current producers have the capacity to produce up to 20,800 
mt/yr Cb as contained in ferrocolumbium. However, due to 
low demand, estimates of actual production for 1983 
amounted to only 10,000 mt from the three producing 
operations (6). Obviously, operating mines are producing at 
greatly reduced levels; in fact, at less than 50 pet of capaci- 
ty. Figure 14 demonstrates that at full capacity and current 
demand levels, producers of columbium have the potential 
to supply projected annual MEC demand into the next cen- 
tury. 

Annual availability curves for nonproducing deposits at a 
total cost of $6/lb, $12/lb and $24/lb. (including a 15-pct 
DCFROR) are shown in figure 15. This figure demonstrates 
that significantly higher prices than current levels must 
prevail in order to cover the high costs of production 



associated with these properties. At a total cost of $6/lb or 
less for columbium contained in ferrocolumbium, non- 
producers have a combined capacity of nearly 4,000 mt/yr. 
An additional 7,000 mt/yr is potentially available at a cost of 
production up to $12/lb. At a maximum total cost of $24/lb, 
the potential availability from nonproducers could increase 
to 20,000 mt/yr. 

Figure 16 shows potential annual availability of colum- 
bium and total cost for nonproducers 5, 10, and 20 yr from 
the study date 'N'. Figures 15 and 16 show production from 
nonproducers would peak 8 to 15 yr after the base year 'N', 
then gradually decrease. This decline in production would 
continue as current resources were depleted, assuming ad- 
ditional resources were not discovered and technological im- 
provements were not made to process lower-grade 
materials. 

Though unlikely, it is important to consider the effects of 
a cut off of production by Brazil on MEC availability of co- 
lumbium and its ramifications regarding U.S. industries 
(fig. 17). Brazilian production presently accounts for almost 
70 pet of MEC ferrocolumbium. This figure assumes that 
the only remaining producer, Niobec, would maintain a 
stable level of production but could not respond to such an 
increased demand. To maintain the estimated 1983 produc- 
tion levels of 10,000 mt (fig. 16) would require a total cost of 
production of up to $12/lb contained columbium. In addition, 
it would require approximately 6 to 8 yr to achieve this pro- 
duction level. A total cost of approximately $24/lb would be 
required to reach existing capacity levels. This scenario 
reiterates Brazil's importance to the MEC columbium in- 
dustry. 



17 




10 
1984 



1988 1992 1996 2000 

FIGURE 14.— Potential annual production from producing mlnoa. 



2004 



O 



2 

00 



o 
o 

UJ 

-J 

00 

< 
& 
5 

o 

UJ 

or 





N 


r J ' r - 1 — 

Year preproduction 
development begins 


1 


1 


i "T" 


— 1 

\ 
\ 
\ 


20 
15 


/ 
/ 
/ 
/ 
/ 
/ 
/ 
/ 
/ 
/ 
/ 






""^^l 24.00 
$12.00 


IO 
5 


( 

1 
1 

/ .•• 

/ : 

l •' ^ 






$6.00 


• 

• 




i 


• 


i i 


1 





e 1 1 JL 



N N+2 N+4 N+6 N+8 N+K) N+12 N+14 N+16 N+18 N+20 

YEAR 



FIGURE 15.— Potential annual production from selected nonproducers at selected ranges of total production costs. 



18 



25 



20 



-e9- 

cd 15 
0> 



c 
o 

»-* 

o 
o 



10 



< 
+- 
o 



N Year preproduction 
development begins 



± 



N + 201 



_L 



N + IO 




5 10 15 

ANNUAL RECOVERABLE COLUMBIUM, I0 3 mt 

FIGURE 16.— Potential annual production from nonproducers for selected years. 



20 



O 



3 
CD 

3 
_J 

o 
o 

UJ 

_» 

m 
< 

UJ 

3 

o 

UJ 



£D 


I I — I 1 1 

N Year preproduction 


— i 1 1 — ■ i 












20 
15 


/ 
/ 

/ 
/ 
/ 
/ 
/ 
/ 
/ 
/ 
S 
S 
/ 


" ~ ^ $24.00 

\ 
\ 
V 

$12.00 




1 

1 
1 


\ 


10 


1 




r ~ 






$6.00 




5 


/ / /^ 


i i i l 






/••■ / 





1 i i i i 



N+2 N+4 N+6 N+8 N+K) N+12 N+W N+16 N+18 N+20 

YEAR 



FIGURE 17.— Potential annual production from selected mines and deposits excluding Brazil. 



19 



CONCLUSION 



Columbium is used primarily as an alloying element in 
high-strength, low-alloy steels and superalloys. For this pur- 
pose, approximately 85 to 90 pet of the columbium con- 
sumed is processed to ferrocolumbium for use in the steel in- 
dustry. Most of the remainder is upgraded to high-purity 
columbium products for use in cobalt, nickel, and iron-based 
superalloys and superconductors. Columbium has not been 
mined commercially in the United States for many years, 
and U.S. ferrocolumbium producers rely solely on colum- 
bium imports. 

A total of 19 deposits (3 producing mines and 16 non- 
producers) were examined to determine MEC availability of 
columbium. The selected deposits included all known 
resources of columbium, meeting the criteria for this study. 

In situ demonstrated resources total over 946 Mmt for the 
19 deposits. Total columbiifm contained in these resources 
amounts to approximately 5.36 Mmt. This figure includes 
3.25 Mmt in Brazil, 1.37 Mmt in North America (Canada 
and the United States), and 0.75 Mmt in Africa (Kenya, 
Uganda, Tanzania, and Zaire). In all cases, columbium oc- 
curs in the mineral form of pyrochlore or its barium- 
strontium analog, pandaite, and is found in association with 
the carbonatite member of alkalic-granite complexes. All 
pyrochlore is currently mined from carbonatite deposits. 

In the past, pegmatitic rocks have served as the principal 
source of columbium as contained in the mineral columbite. 
However, due to the abundance and increased utilization of 
pyrochlore ore, pegmatitic sources of columbite have been 
reduced to a less than 5-pct share of the MEC market for 
columbium 

In terms of potential total availability, Brazil is the largest 
and lowest-cost source of recoverable columbium in the 
MEC. Total recoverable columbium (contained as 65 to 66 
pet in ferrocolumbium) in Brazil amounts to 69 pet (2.39 
Mmt) of the MEC supply. Recoverable columbium resources 



from the Americas account for over 90 pet of the total MEC 
resources studied, totaling 3.14 Mmt. 

Current producers of columbium examined for this study 
include the Araxa and Catalao mines in Brazil, and the 
Niobec mine in Canada. Combined, these mines contain suf- 
ficient resources to supply the estimated cumulative MEC 
columbium demand through the year 2000, based on a 
5.1-pct annual growth rate. 

Potentially recoverable columbium resources from MEC 
nonproducers total 1.05 Mmt. Of this, only 8 pet or 0.08 
Mmt are available at a total cost of production (including a 
1 5-pct DCFROR) at, or below, the January 1984 market 
price of $6/lb Cb contained in ferrocolumbium. A cost of 
$12/lb, comparable to twice the current market price, is re- 
quired to make available 40 pet of the recoverable colum- 
bium contained in nonproducing deposits. Even then, this 
amounts to only 12 pet of the total available from all studied 
deposits. 

The United States is totally dependent upon foreign 
sources of columbium, principally in the forms of fer- 
rocolumbium for steelmaking from Brazil and pyrochlore 
concentrates from Canada. Furthermore, Brazil has in- 
creased its production of ferrocolumbium and other high- 
grade columbium products in recent years, resulting in a 
decrease in U.S. production. Twenty years ago, the United 
States produced nearly all its ferrocolumbium; today, U.S. 
production has declined to 25 pet. Brazil's abundant, low- 
cost supplies may continue to increase U.S. dependency on 
that country for the high-grade columbium products used in 
superalloys. Analyses indicate that columbium is available 
from undeveloped deposits outside of Brazil but at costs of 
production significantly greater than current costs (even at 
a 0-pct DCFROR). Also, these deposits require a period of 
up to 8 yr to develop. As a result, Brazil is expected to main- 
tain its position as the world's major columbium producer, 
into the foreseeable future. 



34S7 47 



20 



REFERENCES 



1. Cunningham, L. D. Columbium and Tantalum. Ch. in BuMines 
Minerals Yearbook 1982, v. 1, pp. 259-269. 

2. Cunningham, L. D. Columbium. BuMines Mineral Commodity 
Profile, 1983, 14 pp. 

3. Manker, Edgar A. Columbium- An Outlook. CIM Bull., v. 74, 
No. 832, 1981, pp. 93-99. 

4. Cunningham, L. D. Columbium. Sec. in BuMines Mineral 
Commodity Summaries 1985, pp. 38-39. 

5. Mining Journal (London). Zaire Reaps Some Rewards. V. 305., 
No. 7822, July 19, 1985, pp. 37-39. 

6. Cunningham, L. D. Columbium and Tantalum. Ch. in BuMines 
Minerals Yearbook 1983, v. 1, pp. 265-275. 

7. Cunningham, L. D. Columbium. Sec. in BuMines Mineral 
Commodity Summaries 1983, pp. 38-39. 

8. Kuestermeyer, A.L., and Scott, R.J. The Development of 
Engineering and Cost Data for Foreign Columbium, Tantalum, 
Mercury, and Molybdenum Properties (contract J0225022, Pin- 
cock, Allen, & Holt, Inc.). BuMines OFR 84-85, 1985, 20 pp.; NTIS 
PB 85-215325. 

9. U.S. Geological Survey and U.S. Bureau of Mines. Principles 
of a Resource/Reserve Classification for Minerals. U.S. Geol. Surv. 
Circ. 831, 1980, 5 pp. 

10. Jones, T: S. Columbium. Ch. in Mineral Facts and Problems, 
1980 Edition. BuMines B 671, pp. 215-225. 

11. Parker, R. L., and J. W. Adams. Niobium (Columbium) and 
Tantalum. Ch. in United States Mineral Resources, ed. by D. A. 
Brobst and W. P. Pratt. U.S. Geol. Surv. Prof. Paper 820, 1973, pp. 
443-454. 

12. Dawson, K. R. Niobium (Columbium) and Tantalum in 
Canada. Geol. Surv. Can. Econ. Geol. Rep. 29, 1974, pp. 19-33. 



13. Hyndman, D. W. Petrology of Igneous and Metamorphic 
Rocks, McGraw-Hill, 1972, pp. 207-222. 

14. de Souza Paraiso, O. and de Fuccio Jr., R. Araxa Niobium 
Mine. Min. Mag., v. 146, No. 2, Feb. 1982, pp. 134-147. 

15. Clement, G. K., Jr., R. L. Miller, P. A. Seibert, L. Avery, and 
H. Bennett. Capital and Operating Cost Estimating System 
Manual for Mining and Beneficiation of Metallic and Nonmetallic 
Minerals Except Fossil Fuels in the United States and Canada. 
BuMines Special Publ., 1980, 149 pp. Also available as: 

STRAAM Engineers, Inc. Capital and Operating Cost 
Estimating System Handbook -Mining and Beneficiation of 
Metallic and Nonmetallic Minerals Except Fossil Fuels in the 
United States and Canada. Submitted to the Bureau of Mines under 
contract J0255026, 1977, 374 pp.; available from the Minerals 
Availability Field Office, Bureau of Mines, Denver, CO. 

16. Davidoff, R. L. Supply Analysis Model (SAM): A Minerals 
Availability System Methodology, BuMines IC 8820, 1980, 45 pp. 
149 pp. 

17. Stermole, F. J. Economic Evaluation and Investment Deci- 
sion Methods. Investment Evaluations Corp., Golden, CO, 1974, 
449 pp. 

18. Mining Magazine. Brazilian Niobium Find. V. 151, No. 1, 
July 1984, p. 11. 

19. Harrop, M. D. Columbium-Recovering Steel Output Sparks 
U.S. Offtake 21.6%. Eng. and Min. J., v. 186, No. 3, Mar. 1985, pp. 
100-102. 

20. National Materials Advisory Board. Tantalum and Colum- 
bium Supply and Demand Outlook. Natl. Acad. Sci., NMAB-391, 
1982, 184 pp. 



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